Posted by Vishva News Reporter on September 11, 2004


When you careful listen to we humans talk, each of us is always saying:

  • I have done this,
  • I can do this,
  • without me this would not have happened,
  • you cannot do this by yourself,
  • what do you think you are....

and so many such statements which gives self-importance and makes one believe that the entire world cannot exist without oneself.....

However, all the above egoistic notions in oneself can be torpedoed very easily if you compare what a single cell in your body does every millisecond of your life compared to what you do ever minute, hour, daily, weekly and monthly....the comparision will make you shut up for ever because as "YOU" and "I" we do not do anything near and profound as a cell in our body does every millisecond of our lives....

Here are some comparative facts which will start making you feel ashamed of your ego saying all the things you say as noted in the first paragraph above..

  • compared to your body size, you can put 40 of your body cells in a millimeter of space.
  • each of your cell is about 90 percent water....
  • a cell has 13 presently known different kind of very complex factories that produces everything to keep you alive, make you grow and empower you to function in everything you do every second of your living moment...however you have to go and buy everything for your physical needs which are produced by more than 13 very rudimentary factories compared to the factories a cell has....(see the cell diagram on the WIKIPEDIA - CELL BIOLOGY. web site )
  • a cell has pumps to move things in and out of the cell such as water and other solutions, structural components to keep its overall shapes and compartments to separate all the 13 factories and generators of electrical  power for making many of its factories work...
  • however a cell never let you know what it does for you but you must let everybody know if you do anything....
  • a cell divides and replicates itself every 24 hours or within its pre-determined life span and destroy its old self to continue its existence...but who tells it to do so? You do not even know that this is happening in your body. The only time you know it when you have cancer. Cancer is cell division and replication at an uncontrolled rate just as in a atomic bomb which explodes and your body literally explodes due to cancer...

So then in the scientific manner of thinking, the questions arises "who makes your cell functional?".....

The current science says it is the DNA and the genes in DNA contained in the chromosomes located in the nucleus of each cell of any living being from a tiny organism to human to dinosaurs....But then who makes the DNA and the gene functional.....

In the study of veD which is sNskRUt language word meaning SCIENCES OF CREATION AND will find that your aat`maa (soul) is the one which empowers your cell and the body including everything else like your mind, intelligence, emotions, attention, intuition, memory, feelings, joy, happiness, pain, unhappiness, to do or not to do prompting, right or wrong notions, etc which the current science has tremendous difficulty to understand as you cannot see or touch or measure your mind, intelligence, emotions, attention, intuition, memory, feelings, joy, happiness, pain, unhappiness, to do or not to do prompting, right or wrong notions,etc....

PVAF would like to have your thoughts on who powers your cell and you while you are alive......Just click on the POST A COMMENT button in the header of this news item and share away your thoughts and knowledge...

(The above write-up was from the veD library of SRii chmpklaal Daajibhaai misTRii of Edmnton, Alberta, Canada as part of the study and sharing of veD knowledge at PVAF with all humanity....)

And may be if you are of inquisitive type to know your cell in general detail that any normal human being can understand without a PhD or a medical degree please click on the this web address at WIKIPEDIA - CELL BIOLOGY.....or if you wish to read wikipedia information on this web site please click on the next line....some of the diagrams may not be visible and you will have to go on to the wikipedia web site...please also note that you can click on each of the blue highlite to learn more about that word or phrase in the wikipedia writing...

Cell (biology)

From Wikipedia, the free encyclopedia.

Cells in culture, stained for keratin
Cells in culture, stained for keratin

In biology, the cell is the fundamental structural and functional unit of all living organisms. The cell theory, first developed in the 19th century, states that all organisms are composed of one or more cells; all cells come from preexisting cells; all vital functions of an organism occur within cells and that cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

Contents [hide]


Surface of an embryonic mouse cell with scale indicated
Surface of an embryonic mouse cell with scale indicated


Organisms vary from single cells (called single-celled organisms) that function and survive more or less independently, through colonial forms withcells living together, to multicellular forms in which cells are specialized and do not generally survive once separated. There are 220 types of cells and tissues that make up the multicellular human body.


Types of cells: prokaryotic and eukaryotic

Two basic types of cells are described: prokaryotic and eukaryotic. Prokaryotic cells are structurally simple. They are found only in single-celled and colonial organisms. In the three-domain system of Scientific classification, prokaryotic cells are placed in the domains Archaea and Eubacteria. Eukaryotic cells have organelles with their own cell membranes. Single-celled eukaryotic organisms are very diverse, but many colonial and multicellular forms also exist. (The multicellular kingdoms: Animalia, Plantae and Fungi, are all eukaryotic.)


Comparison of features of prokaroytic and eukaryotic cells
  Prokaryotes Eukaryotes
typical organisms bacteria protists, fungi, plants, animals
typical size ~ 1-10 µm ~ 10-100 µm (sperm cells, apart from the tail, are smaller)
type of nucleus nucleoid region; no real nucleus real nucleus with double membrane
DNA circular (usually) linear molecules (chromosomes) with histone proteins
RNA-/protein-synthesis coupled in cytoplasm RNA-synthesis inside the nucleus
protein synthesis in cytoplasm
ribosomes 50S+30S 60S+40S
cytoplasmatic structure very few structures highly structured by intercellular membranes and a cytoskeleton
cell movement flagella made of flagellin flagella and cilia made of tubulin
mitochondria none one to several dozen (though some lack mitochondria)
chloroplasts none in algae and plants
organization usually single cells single cells, colonies, higher organisms with specialized cells
cell division Binary fission (simple division) Mitosis (core division)
Cytokinesis (cytoplasmatic division)

Prokaryotic cells

  • The cytoplasm of prokaryotes (the liquid which makes up most of the cell volume) is diffuse and granular due to ribosomes (protein factories) floating in the cell.
  • The plasma membrane (a phospholipid bilayer) separates the interior of the cell from its environment and serves as a filter and communications beacon.
  • Most prokaryotes have a cell wall (some exceptions are Mycoplasma (a bacterium) and Thermoplasma (an archaeon)). It consists of peptidoglycan in bacteria, and acts as an additional barrier against exterior forces. It also prevents the cell from "exploding" from osmotic pressure against a hypotonic environment.
  • A prokaryotic chromosome is usually a circular molecule (an exception is that of the bacterium Borrelia burgdorferi, which causes Lyme disease). Even without a real nucleus, the DNA is somehow condensed in a nucleoid. Prokaryotes can carry extrachromosomal DNA elements called plasmids, which are usually circular. Plasmids can carry additional functions, such as antibiotic resistance.
  • Some prokaryotes have flagella which enable them to move actively instead of passively drifting.

Eukaryotic cells

Eukaryotic cells are highly organized and composed of structurs known as organelles that perform specific functions.

  • The cytoplasm of eukaryotes does not appear as granular as that of prokaryotes, since an important part of the ribosomes are bound to the endoplasmic reticulum.
  • The plasma membrane resembles that of prokaryotes in function, with minor differences in the setup. Cell walls may or may not be present.
  • The eukaryotic DNA is organized in one or more linear molecules, called chromosomes, which are highly condensed (e.g. folded around histones). All chromosomal DNA is stored in the cell nucleus, separated from the cytoplasm by a membrane. Some eukaryotic organelles can contain some DNA.
  • Eukaryotes can become mobile using cilia or flagella. The flagella are more complex than those of prokaryotes.

A typical animal cell


Drawing of a cell (click to enlarge)
Drawing of a cell (click to enlarge)
  1. Nucleolus
  2. Nucleus
  3. Ribosome
  4. Vesicle
  5. Rough endoplasmic reticulum (ER)
  6. Golgi apparatus
  7. Microtubule
  8. Smooth ER
  9. Mitochondria
  10. Vacuole
  11. Cytoplasm
  12. Lysosome
  13. Centrioles

Organelles (see diagram above)



A typical plant cell


  1. Tonoplast
  2. Central vacuole
  3. Nucelus
  4. Rough endoplasmic reticulum
  5. Smooth endoplasmic reticulum
  6. Peroxisome
  7. Golgi apparatus
  8. Ribosomes
  9. Chloroplast
  10. Microfilaments
  11. Microtubules
  12. Mitochondrion


  1. Plasma membrane
  2. Cell wall
  3. Plasmodesma

Human body cells

The body contains trillions of cells.



All cells share several abilities:

Many cell functions are carried out by enzymes.


Energy use

The functioning of a cell depends upon its ability to extract and use chemical energy stored in organic molecules. This energy is derived from metabolic pathways.


Moving of proteins

A typical mammalian cell contains up to 10,000 different proteins.


The origin of cells

The origin of cells has much to do with the origin of life, and was one of the most important steps in evolution of life as we know it. The birth of the cell marked the passage from prebiotic chemistry to biological life.


Origin of the first cell

If we see life forms from the point of view of replicators, that is DNA molecules in the actual life, cells satisfy two fundamental conditions : protection from the outside environment and confinement of biochemical activity. The former condition is needed to maintain the fragile DNA chains stable in a varying and sometimes aggressive environment, and probably was the main reason for which cells evolved. The latter is fundamental for the evolution of biological complexity. If we have,let's imagine, freely-floating DNA molecules that code for enzymes that are not enclosed into cells, the enzymes that advantage a given DNA molecule (for example,by producing nucleotides) will automatically advantage also the neighbouring DNA molecules. You can see it as "parasitism by default". Therefore the evolutive pressure on DNA molecules will be much lower,since there is not a definitive advantage for the "lucky" DNA molecule that produces the better enzyme over the others: all molecules in a given neighbourhood are almost equally advantaged. If we have the DNA molecule enclosed in a cell, then the enzymes coded from the molecule will be kept close to the DNA molecule itself. The DNA molecule will directly enjoy the benefits of the enzymes it codes, and not of others. This means other DNA molecules can't benefit of a positive mutation in a neighbouring molecule : this means that positive mutations give immediate and selective advantage to the replicator bearing it, and not on others. This is thought to have been the one of the main driving force of evolution of life as we know it. (Note. This is more a metaphor given for simplicity than a possible truth, since probably the earliest molecules of life, probably up to the stage of cellular life, were RNA molecules, acting both as replicators and enzymes : see RNA world hypothesis . But the core of the reasoning is the same.)

Biochemically, cell-like spheroids formed by proteinoids are observed by heating aminoacids with phosphoric acid as a catalyst. They bear much of the basic features provided by cell membranes. Proteinoid-based protocells enclosing RNA molecules could (but not necessarily should) have been the first cellular life forms on Earth.


Origin of the eukaryotic cell

The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. It is almost certain that DNA-bearing organelles like the mitochondria and the chloroplasts are what remains of ancient symbiotic oxygen-breathing bacteria and cyanobacteria, respectively, where the rest of the cell seems to be derived from an ancestral archaean prokaryote cell. There is still considerable debate on if organelles like the hydrogenosome predated the origin of mitochondria, or viceversa : see the hydrogen hypothesis for the origin of eukaryotic cells.



...I could exceedingly plainly perceive it to be all perforated and porous, much like a Honeycomb...these pores or cells, were not very deep, but consisted of a great many little boxes... – Hooke describing his observations on a thin slice of cork.


The word cell comes from the Latin cella, a small room.


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